<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Mail
 * @subpackage Protocol
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Smtp.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Mime
 */
require_once 'Zend/Mime.php';
/**
 *
 * @see Zend_Mail_Protocol_Abstract
 */
require_once 'Zend/Mail/Protocol/Abstract.php';

/**
 * Smtp implementation of Zend_Mail_Protocol_Abstract
 * Minimum implementation according to RFC2821: EHLO, MAIL FROM, RCPT TO, DATA, RSET, NOOP, QUIT
 * @category Zend
 * @package Zend_Mail
 * @subpackage Protocol
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Mail_Protocol_Smtp extends Zend_Mail_Protocol_Abstract {

    /**
     * The transport method for the socket
     * @var string
     */
    protected $_transport = 'tcp';

    /**
     * Indicates that a session is requested to be secure
     * @var string
     */
    protected $_secure;

    /**
     * Indicates an smtp session has been started by the HELO command
     * @var boolean
     */
    protected $_sess = false;

    /**
     * Indicates the HELO command has been issues
     * @var unknown_type
     */
    protected $_helo = false;

    /**
     * Indicates an smtp AUTH has been issued and authenticated
     * @var unknown_type
     */
    protected $_auth = false;

    /**
     * Indicates a MAIL command has been issued
     * @var unknown_type
     */
    protected $_mail = false;

    /**
     * Indicates one or more RCTP commands have been issued
     * @var unknown_type
     */
    protected $_rcpt = false;

    /**
     * Indicates that DATA has been issued and sent
     * @var unknown_type
     */
    protected $_data = null;

    /**
     * Constructor.
     * @param string $host
     * @param integer $port
     * @param array $config
     * @return void
     * @throws Zend_Mail_Protocol_Exception
     */
    public function __construct ($host = '127.0.0.1', $port = null, array $config = array()) {
        if (isset ($config['ssl'])) {
            switch (strtolower ($config['ssl'])) {
                case 'tls' :
                    $this -> _secure = 'tls';
                    break;
                case 'ssl' :
                    $this -> _transport = 'ssl';
                    $this -> _secure = 'ssl';
                    if ($port == null) {
                        $port = 465;
                    }
                    break;
                default :
                    /**
                     *
                     * @see Zend_Mail_Protocol_Exception
                     */
                    require_once 'Zend/Mail/Protocol/Exception.php';
                    throw new Zend_Mail_Protocol_Exception ($config['ssl'] . ' is unsupported SSL type');
                    break;
            }
        }
        // If no port has been specified then check the master PHP ini file. Defaults to 25 if the ini setting is null.
        if ($port == null) {
            if (($port = ini_get ('smtp_port')) == '') {
                $port = 25;
            }
        }
        parent::__construct ($host, $port);
    }

    /**
     * Connect to the server with the parameters given in the constructor.
     * @return boolean
     */
    public function connect () {
        return $this -> _connect ($this -> _transport . '://' . $this -> _host . ':' . $this -> _port);
    }

    /**
     * Initiate HELO/EHLO sequence and set flag to indicate valid smtp session
     * @param string $host The client hostname or IP address (default: 127.0.0.1)
     * @throws Zend_Mail_Protocol_Exception
     * @return void
     */
    public function helo ($host = '127.0.0.1') {
        // Respect RFC 2821 and disallow HELO attempts if session is already initiated.
        if ($this -> _sess === true) {
            /**
             *
             * @see Zend_Mail_Protocol_Exception
             */
            require_once 'Zend/Mail/Protocol/Exception.php';
            throw new Zend_Mail_Protocol_Exception ('Cannot issue HELO to existing session');
        }
        // Validate client hostname
        if ( ! $this -> _validHost -> isValid ($host)) {
            /**
             *
             * @see Zend_Mail_Protocol_Exception
             */
            require_once 'Zend/Mail/Protocol/Exception.php';
            throw new Zend_Mail_Protocol_Exception (join (', ', $this -> _validHost -> getMessages ()));
        }
        // Initiate helo sequence
        $this -> _expect (220, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
        $this -> _ehlo ($host);
        // If a TLS session is required, commence negotiation
        if ($this -> _secure == 'tls') {
            $this -> _send ('STARTTLS');
            $this -> _expect (220, 180);
            if ( ! stream_socket_enable_crypto ($this -> _socket, true, STREAM_CRYPTO_METHOD_TLS_CLIENT)) {
                /**
                 *
                 * @see Zend_Mail_Protocol_Exception
                 */
                require_once 'Zend/Mail/Protocol/Exception.php';
                throw new Zend_Mail_Protocol_Exception ('Unable to connect via TLS');
            }
            $this -> _ehlo ($host);
        }
        $this -> _startSession ();
        $this -> auth ();
    }

    /**
     * Send EHLO or HELO depending on capabilities of smtp host
     * @param string $host The client hostname or IP address (default: 127.0.0.1)
     * @throws Zend_Mail_Protocol_Exception
     * @return void
     */
    protected function _ehlo ($host) {
        // Support for older, less-compliant remote servers. Tries multiple attempts of EHLO or HELO.
        try {
            $this -> _send ('EHLO ' . $host);
            $this -> _expect (250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
        } catch (Zend_Mail_Protocol_Exception $e) {
            $this -> _send ('HELO ' . $host);
            $this -> _expect (250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
        } catch (Zend_Mail_Protocol_Exception $e) {
            throw $e;
        }
    }

    /**
     * Issues MAIL command
     * @param string $from Sender mailbox
     * @throws Zend_Mail_Protocol_Exception
     * @return void
     */
    public function mail ($from) {
        if ($this -> _sess !== true) {
            /**
             *
             * @see Zend_Mail_Protocol_Exception
             */
            require_once 'Zend/Mail/Protocol/Exception.php';
            throw new Zend_Mail_Protocol_Exception ('A valid session has not been started');
        }
        $this -> _send ('MAIL FROM:<' . $from . '>');
        $this -> _expect (250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
                                     // Set mail to true, clear recipients and any existing data flags as per 4.1.1.2 of RFC 2821
        $this -> _mail = true;
        $this -> _rcpt = false;
        $this -> _data = false;
    }

    /**
     * Issues RCPT command
     * @param string $to Receiver(s) mailbox
     * @throws Zend_Mail_Protocol_Exception
     * @return void
     */
    public function rcpt ($to) {
        if ($this -> _mail !== true) {
            /**
             *
             * @see Zend_Mail_Protocol_Exception
             */
            require_once 'Zend/Mail/Protocol/Exception.php';
            throw new Zend_Mail_Protocol_Exception ('No sender reverse path has been supplied');
        }
        // Set rcpt to true, as per 4.1.1.3 of RFC 2821
        $this -> _send ('RCPT TO:<' . $to . '>');
        $this -> _expect (array(250, 251), 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
        $this -> _rcpt = true;
    }

    /**
     * Issues DATA command
     * @param string $data
     * @throws Zend_Mail_Protocol_Exception
     * @return void
     */
    public function data ($data) {
        // Ensure recipients have been set
        if ($this -> _rcpt !== true) {
            /**
             *
             * @see Zend_Mail_Protocol_Exception
             */
            require_once 'Zend/Mail/Protocol/Exception.php';
            throw new Zend_Mail_Protocol_Exception ('No recipient forward path has been supplied');
        }
        $this -> _send ('DATA');
        $this -> _expect (354, 120); // Timeout set for 2 minutes as per RFC 2821 4.5.3.2
        foreach (explode (Zend_Mime::LINEEND, $data) as $line) {
            if (strpos ($line, '.') === 0) {
                // Escape lines prefixed with a '.'
                $line = '.' . $line;
            }
            $this -> _send ($line);
        }
        $this -> _send ('.');
        $this -> _expect (250, 600); // Timeout set for 10 minutes as per RFC 2821 4.5.3.2
        $this -> _data = true;
    }

    /**
     * Issues the RSET command and validates answer
     * Can be used to restore a clean smtp communication state when a transaction has been cancelled or commencing a new transaction.
     * @return void
     */
    public function rset () {
        $this -> _send ('RSET');
        // MS ESMTP doesn't follow RFC, see [ZF-1377]
        $this -> _expect (array(250, 220));
        $this -> _mail = false;
        $this -> _rcpt = false;
        $this -> _data = false;
    }

    /**
     * Issues the NOOP command and validates answer
     * Not used by Zend_Mail, could be used to keep a connection alive or check if it is still open.
     * @return void
     */
    public function noop () {
        $this -> _send ('NOOP');
        $this -> _expect (250, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
    }

    /**
     * Issues the VRFY command and validates answer
     * Not used by Zend_Mail.
     * @param string $user User Name or eMail to verify
     * @return void
     */
    public function vrfy ($user) {
        $this -> _send ('VRFY ' . $user);
        $this -> _expect (array(250, 251, 252), 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
    }

    /**
     * Issues the QUIT command and clears the current session
     * @return void
     */
    public function quit () {
        if ($this -> _sess) {
            $this -> _send ('QUIT');
            $this -> _expect (221, 300); // Timeout set for 5 minutes as per RFC 2821 4.5.3.2
            $this -> _stopSession ();
        }
    }

    /**
     * Default authentication method
     * This default method is implemented by AUTH adapters to properly authenticate to a remote host.
     * @throws Zend_Mail_Protocol_Exception
     * @return void
     */
    public function auth () {
        if ($this -> _auth === true) {
            /**
             *
             * @see Zend_Mail_Protocol_Exception
             */
            require_once 'Zend/Mail/Protocol/Exception.php';
            throw new Zend_Mail_Protocol_Exception ('Already authenticated for this session');
        }
    }

    /**
     * Closes connection
     * @return void
     */
    public function disconnect () {
        $this -> _disconnect ();
    }

    /**
     * Start mail session
     * @return void
     */
    protected function _startSession () {
        $this -> _sess = true;
    }

    /**
     * Stop mail session
     * @return void
     */
    protected function _stopSession () {
        $this -> _sess = false;
    }

}
